2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
18 #include <linux/sched.h>
19 #include <linux/pagemap.h>
20 #include <linux/writeback.h>
21 #include <linux/blkdev.h>
26 #include "print-tree.h"
27 #include "transaction.h"
30 #include "ref-cache.h"
32 static int finish_current_insert(struct btrfs_trans_handle *trans, struct
33 btrfs_root *extent_root);
34 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
35 btrfs_root *extent_root);
36 static struct btrfs_block_group_cache *
37 __btrfs_find_block_group(struct btrfs_root *root,
38 struct btrfs_block_group_cache *hint,
39 u64 search_start, int data, int owner);
41 void maybe_lock_mutex(struct btrfs_root *root)
43 if (root != root->fs_info->extent_root &&
44 root != root->fs_info->chunk_root &&
45 root != root->fs_info->dev_root) {
46 mutex_lock(&root->fs_info->alloc_mutex);
50 void maybe_unlock_mutex(struct btrfs_root *root)
52 if (root != root->fs_info->extent_root &&
53 root != root->fs_info->chunk_root &&
54 root != root->fs_info->dev_root) {
55 mutex_unlock(&root->fs_info->alloc_mutex);
59 static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
61 return (cache->flags & bits) == bits;
65 * this adds the block group to the fs_info rb tree for the block group
68 int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
69 struct btrfs_block_group_cache *block_group)
72 struct rb_node *parent = NULL;
73 struct btrfs_block_group_cache *cache;
75 spin_lock(&info->block_group_cache_lock);
76 p = &info->block_group_cache_tree.rb_node;
80 cache = rb_entry(parent, struct btrfs_block_group_cache,
82 if (block_group->key.objectid < cache->key.objectid) {
84 } else if (block_group->key.objectid > cache->key.objectid) {
87 spin_unlock(&info->block_group_cache_lock);
92 rb_link_node(&block_group->cache_node, parent, p);
93 rb_insert_color(&block_group->cache_node,
94 &info->block_group_cache_tree);
95 spin_unlock(&info->block_group_cache_lock);
101 * This will return the block group at or after bytenr if contains is 0, else
102 * it will return the block group that contains the bytenr
104 static struct btrfs_block_group_cache *
105 block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
108 struct btrfs_block_group_cache *cache, *ret = NULL;
112 spin_lock(&info->block_group_cache_lock);
113 n = info->block_group_cache_tree.rb_node;
116 cache = rb_entry(n, struct btrfs_block_group_cache,
118 end = cache->key.objectid + cache->key.offset - 1;
119 start = cache->key.objectid;
121 if (bytenr < start) {
122 if (!contains && (!ret || start < ret->key.objectid))
125 } else if (bytenr > start) {
126 if (contains && bytenr <= end) {
136 spin_unlock(&info->block_group_cache_lock);
142 * this is only called by cache_block_group, since we could have freed extents
143 * we need to check the pinned_extents for any extents that can't be used yet
144 * since their free space will be released as soon as the transaction commits.
146 static int add_new_free_space(struct btrfs_block_group_cache *block_group,
147 struct btrfs_fs_info *info, u64 start, u64 end)
149 u64 extent_start, extent_end, size;
152 while (start < end) {
153 ret = find_first_extent_bit(&info->pinned_extents, start,
154 &extent_start, &extent_end,
159 if (extent_start == start) {
160 start = extent_end + 1;
161 } else if (extent_start > start && extent_start < end) {
162 size = extent_start - start;
163 ret = btrfs_add_free_space(block_group, start, size);
165 start = extent_end + 1;
173 ret = btrfs_add_free_space(block_group, start, size);
180 static int cache_block_group(struct btrfs_root *root,
181 struct btrfs_block_group_cache *block_group)
183 struct btrfs_path *path;
185 struct btrfs_key key;
186 struct extent_buffer *leaf;
195 root = root->fs_info->extent_root;
197 if (block_group->cached)
200 path = btrfs_alloc_path();
206 * we get into deadlocks with paths held by callers of this function.
207 * since the alloc_mutex is protecting things right now, just
208 * skip the locking here
210 path->skip_locking = 1;
211 first_free = max_t(u64, block_group->key.objectid,
212 BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE);
213 key.objectid = block_group->key.objectid;
215 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
216 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
219 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
223 leaf = path->nodes[0];
224 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
225 if (key.objectid + key.offset > first_free)
226 first_free = key.objectid + key.offset;
229 leaf = path->nodes[0];
230 slot = path->slots[0];
231 if (slot >= btrfs_header_nritems(leaf)) {
232 ret = btrfs_next_leaf(root, path);
240 btrfs_item_key_to_cpu(leaf, &key, slot);
241 if (key.objectid < block_group->key.objectid)
244 if (key.objectid >= block_group->key.objectid +
245 block_group->key.offset)
248 if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
254 add_new_free_space(block_group, root->fs_info, last,
257 last = key.objectid + key.offset;
266 add_new_free_space(block_group, root->fs_info, last,
267 block_group->key.objectid +
268 block_group->key.offset);
270 block_group->cached = 1;
273 btrfs_free_path(path);
278 * return the block group that starts at or after bytenr
280 struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct
284 struct btrfs_block_group_cache *cache;
286 cache = block_group_cache_tree_search(info, bytenr, 0);
292 * return the block group that contains teh given bytenr
294 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
298 struct btrfs_block_group_cache *cache;
300 cache = block_group_cache_tree_search(info, bytenr, 1);
305 static int noinline find_free_space(struct btrfs_root *root,
306 struct btrfs_block_group_cache **cache_ret,
307 u64 *start_ret, u64 num, int data)
310 struct btrfs_block_group_cache *cache = *cache_ret;
311 struct btrfs_free_space *info = NULL;
314 u64 search_start = *start_ret;
316 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
317 total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
322 last = max(search_start, cache->key.objectid);
325 ret = cache_block_group(root, cache);
329 if (cache->ro || !block_group_bits(cache, data))
332 info = btrfs_find_free_space(cache, last, num);
334 *start_ret = info->offset;
339 last = cache->key.objectid + cache->key.offset;
341 cache = btrfs_lookup_first_block_group(root->fs_info, last);
342 if (!cache || cache->key.objectid >= total_fs_bytes)
352 static u64 div_factor(u64 num, int factor)
361 static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
364 struct list_head *head = &info->space_info;
365 struct list_head *cur;
366 struct btrfs_space_info *found;
367 list_for_each(cur, head) {
368 found = list_entry(cur, struct btrfs_space_info, list);
369 if (found->flags == flags)
376 static struct btrfs_block_group_cache *
377 __btrfs_find_block_group(struct btrfs_root *root,
378 struct btrfs_block_group_cache *hint,
379 u64 search_start, int data, int owner)
381 struct btrfs_block_group_cache *cache;
382 struct btrfs_block_group_cache *found_group = NULL;
383 struct btrfs_fs_info *info = root->fs_info;
384 struct btrfs_space_info *sinfo;
392 if (data & BTRFS_BLOCK_GROUP_METADATA)
396 struct btrfs_block_group_cache *shint;
397 shint = btrfs_lookup_first_block_group(info, search_start);
398 if (shint && block_group_bits(shint, data) && !shint->ro) {
399 spin_lock(&shint->lock);
400 used = btrfs_block_group_used(&shint->item);
401 if (used + shint->pinned <
402 div_factor(shint->key.offset, factor)) {
403 spin_unlock(&shint->lock);
406 spin_unlock(&shint->lock);
409 if (hint && !hint->ro && block_group_bits(hint, data)) {
410 spin_lock(&hint->lock);
411 used = btrfs_block_group_used(&hint->item);
412 if (used + hint->pinned <
413 div_factor(hint->key.offset, factor)) {
414 spin_unlock(&hint->lock);
417 spin_unlock(&hint->lock);
418 last = hint->key.objectid + hint->key.offset;
421 last = max(hint->key.objectid, search_start);
425 sinfo = __find_space_info(root->fs_info, data);
434 spin_lock(&sinfo->lock);
435 list_for_each(l, &sinfo->block_groups) {
436 struct btrfs_block_group_cache *entry;
437 entry = list_entry(l, struct btrfs_block_group_cache,
439 if ((entry->key.objectid >= last) &&
440 (!cache || (entry->key.objectid <
441 cache->key.objectid)))
444 spin_unlock(&sinfo->lock);
449 spin_lock(&cache->lock);
450 last = cache->key.objectid + cache->key.offset;
451 used = btrfs_block_group_used(&cache->item);
453 if (!cache->ro && block_group_bits(cache, data)) {
454 free_check = div_factor(cache->key.offset, factor);
455 if (used + cache->pinned < free_check) {
457 spin_unlock(&cache->lock);
461 spin_unlock(&cache->lock);
469 if (!full_search && factor < 10) {
479 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
480 struct btrfs_block_group_cache
481 *hint, u64 search_start,
485 struct btrfs_block_group_cache *ret;
486 ret = __btrfs_find_block_group(root, hint, search_start, data, owner);
490 static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation,
491 u64 owner, u64 owner_offset)
493 u32 high_crc = ~(u32)0;
494 u32 low_crc = ~(u32)0;
496 lenum = cpu_to_le64(root_objectid);
497 high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
498 lenum = cpu_to_le64(ref_generation);
499 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
500 if (owner >= BTRFS_FIRST_FREE_OBJECTID) {
501 lenum = cpu_to_le64(owner);
502 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
503 lenum = cpu_to_le64(owner_offset);
504 low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
506 return ((u64)high_crc << 32) | (u64)low_crc;
509 static int match_extent_ref(struct extent_buffer *leaf,
510 struct btrfs_extent_ref *disk_ref,
511 struct btrfs_extent_ref *cpu_ref)
516 if (cpu_ref->objectid)
517 len = sizeof(*cpu_ref);
519 len = 2 * sizeof(u64);
520 ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref,
525 /* simple helper to search for an existing extent at a given offset */
526 int btrfs_lookup_extent(struct btrfs_root *root, struct btrfs_path *path,
530 struct btrfs_key key;
532 maybe_lock_mutex(root);
533 key.objectid = start;
535 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
536 ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
538 maybe_unlock_mutex(root);
542 static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans,
543 struct btrfs_root *root,
544 struct btrfs_path *path, u64 bytenr,
546 u64 ref_generation, u64 owner,
547 u64 owner_offset, int del)
550 struct btrfs_key key;
551 struct btrfs_key found_key;
552 struct btrfs_extent_ref ref;
553 struct extent_buffer *leaf;
554 struct btrfs_extent_ref *disk_ref;
558 btrfs_set_stack_ref_root(&ref, root_objectid);
559 btrfs_set_stack_ref_generation(&ref, ref_generation);
560 btrfs_set_stack_ref_objectid(&ref, owner);
561 btrfs_set_stack_ref_offset(&ref, owner_offset);
563 hash = hash_extent_ref(root_objectid, ref_generation, owner,
566 key.objectid = bytenr;
567 key.type = BTRFS_EXTENT_REF_KEY;
570 ret = btrfs_search_slot(trans, root, &key, path,
574 leaf = path->nodes[0];
576 u32 nritems = btrfs_header_nritems(leaf);
577 if (path->slots[0] >= nritems) {
578 ret2 = btrfs_next_leaf(root, path);
581 leaf = path->nodes[0];
583 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
584 if (found_key.objectid != bytenr ||
585 found_key.type != BTRFS_EXTENT_REF_KEY)
587 key.offset = found_key.offset;
589 btrfs_release_path(root, path);
593 disk_ref = btrfs_item_ptr(path->nodes[0],
595 struct btrfs_extent_ref);
596 if (match_extent_ref(path->nodes[0], disk_ref, &ref)) {
600 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
601 key.offset = found_key.offset + 1;
602 btrfs_release_path(root, path);
609 * Back reference rules. Back refs have three main goals:
611 * 1) differentiate between all holders of references to an extent so that
612 * when a reference is dropped we can make sure it was a valid reference
613 * before freeing the extent.
615 * 2) Provide enough information to quickly find the holders of an extent
616 * if we notice a given block is corrupted or bad.
618 * 3) Make it easy to migrate blocks for FS shrinking or storage pool
619 * maintenance. This is actually the same as #2, but with a slightly
620 * different use case.
622 * File extents can be referenced by:
624 * - multiple snapshots, subvolumes, or different generations in one subvol
625 * - different files inside a single subvolume (in theory, not implemented yet)
626 * - different offsets inside a file (bookend extents in file.c)
628 * The extent ref structure has fields for:
630 * - Objectid of the subvolume root
631 * - Generation number of the tree holding the reference
632 * - objectid of the file holding the reference
633 * - offset in the file corresponding to the key holding the reference
635 * When a file extent is allocated the fields are filled in:
636 * (root_key.objectid, trans->transid, inode objectid, offset in file)
638 * When a leaf is cow'd new references are added for every file extent found
639 * in the leaf. It looks the same as the create case, but trans->transid
640 * will be different when the block is cow'd.
642 * (root_key.objectid, trans->transid, inode objectid, offset in file)
644 * When a file extent is removed either during snapshot deletion or file
645 * truncation, the corresponding back reference is found
648 * (btrfs_header_owner(leaf), btrfs_header_generation(leaf),
649 * inode objectid, offset in file)
651 * Btree extents can be referenced by:
653 * - Different subvolumes
654 * - Different generations of the same subvolume
656 * Storing sufficient information for a full reverse mapping of a btree
657 * block would require storing the lowest key of the block in the backref,
658 * and it would require updating that lowest key either before write out or
659 * every time it changed. Instead, the objectid of the lowest key is stored
660 * along with the level of the tree block. This provides a hint
661 * about where in the btree the block can be found. Searches through the
662 * btree only need to look for a pointer to that block, so they stop one
663 * level higher than the level recorded in the backref.
665 * Some btrees do not do reference counting on their extents. These
666 * include the extent tree and the tree of tree roots. Backrefs for these
667 * trees always have a generation of zero.
669 * When a tree block is created, back references are inserted:
671 * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid)
673 * When a tree block is cow'd in a reference counted root,
674 * new back references are added for all the blocks it points to.
675 * These are of the form (trans->transid will have increased since creation):
677 * (root->root_key.objectid, trans->transid, level, lowest_key_objectid)
679 * Because the lowest_key_objectid and the level are just hints
680 * they are not used when backrefs are deleted. When a backref is deleted:
682 * if backref was for a tree root:
683 * root_objectid = root->root_key.objectid
685 * root_objectid = btrfs_header_owner(parent)
687 * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0)
689 * Back Reference Key hashing:
691 * Back references have four fields, each 64 bits long. Unfortunately,
692 * This is hashed into a single 64 bit number and placed into the key offset.
693 * The key objectid corresponds to the first byte in the extent, and the
694 * key type is set to BTRFS_EXTENT_REF_KEY
696 int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans,
697 struct btrfs_root *root,
698 struct btrfs_path *path, u64 bytenr,
699 u64 root_objectid, u64 ref_generation,
700 u64 owner, u64 owner_offset)
703 struct btrfs_key key;
704 struct btrfs_extent_ref ref;
705 struct btrfs_extent_ref *disk_ref;
708 btrfs_set_stack_ref_root(&ref, root_objectid);
709 btrfs_set_stack_ref_generation(&ref, ref_generation);
710 btrfs_set_stack_ref_objectid(&ref, owner);
711 btrfs_set_stack_ref_offset(&ref, owner_offset);
713 hash = hash_extent_ref(root_objectid, ref_generation, owner,
716 key.objectid = bytenr;
717 key.type = BTRFS_EXTENT_REF_KEY;
719 ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref));
720 while (ret == -EEXIST) {
721 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
722 struct btrfs_extent_ref);
723 if (match_extent_ref(path->nodes[0], disk_ref, &ref))
726 btrfs_release_path(root, path);
727 ret = btrfs_insert_empty_item(trans, root, path, &key,
732 disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
733 struct btrfs_extent_ref);
734 write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref,
736 btrfs_mark_buffer_dirty(path->nodes[0]);
738 btrfs_release_path(root, path);
742 static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
743 struct btrfs_root *root,
744 u64 bytenr, u64 num_bytes,
745 u64 root_objectid, u64 ref_generation,
746 u64 owner, u64 owner_offset)
748 struct btrfs_path *path;
750 struct btrfs_key key;
751 struct extent_buffer *l;
752 struct btrfs_extent_item *item;
755 WARN_ON(num_bytes < root->sectorsize);
756 path = btrfs_alloc_path();
761 key.objectid = bytenr;
762 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
763 key.offset = num_bytes;
764 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
773 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
774 refs = btrfs_extent_refs(l, item);
775 btrfs_set_extent_refs(l, item, refs + 1);
776 btrfs_mark_buffer_dirty(path->nodes[0]);
778 btrfs_release_path(root->fs_info->extent_root, path);
781 ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root,
782 path, bytenr, root_objectid,
783 ref_generation, owner, owner_offset);
785 finish_current_insert(trans, root->fs_info->extent_root);
786 del_pending_extents(trans, root->fs_info->extent_root);
788 btrfs_free_path(path);
792 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
793 struct btrfs_root *root,
794 u64 bytenr, u64 num_bytes,
795 u64 root_objectid, u64 ref_generation,
796 u64 owner, u64 owner_offset)
800 mutex_lock(&root->fs_info->alloc_mutex);
801 ret = __btrfs_inc_extent_ref(trans, root, bytenr, num_bytes,
802 root_objectid, ref_generation,
803 owner, owner_offset);
804 mutex_unlock(&root->fs_info->alloc_mutex);
808 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
809 struct btrfs_root *root)
811 finish_current_insert(trans, root->fs_info->extent_root);
812 del_pending_extents(trans, root->fs_info->extent_root);
816 static int lookup_extent_ref(struct btrfs_trans_handle *trans,
817 struct btrfs_root *root, u64 bytenr,
818 u64 num_bytes, u32 *refs)
820 struct btrfs_path *path;
822 struct btrfs_key key;
823 struct extent_buffer *l;
824 struct btrfs_extent_item *item;
826 WARN_ON(num_bytes < root->sectorsize);
827 path = btrfs_alloc_path();
829 key.objectid = bytenr;
830 key.offset = num_bytes;
831 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
832 ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path,
837 btrfs_print_leaf(root, path->nodes[0]);
838 printk("failed to find block number %Lu\n", bytenr);
842 item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item);
843 *refs = btrfs_extent_refs(l, item);
845 btrfs_free_path(path);
850 static int get_reference_status(struct btrfs_root *root, u64 bytenr,
851 u64 parent_gen, u64 ref_objectid,
852 u64 *min_generation, u32 *ref_count)
854 struct btrfs_root *extent_root = root->fs_info->extent_root;
855 struct btrfs_path *path;
856 struct extent_buffer *leaf;
857 struct btrfs_extent_ref *ref_item;
858 struct btrfs_key key;
859 struct btrfs_key found_key;
860 u64 root_objectid = root->root_key.objectid;
865 key.objectid = bytenr;
867 key.type = BTRFS_EXTENT_ITEM_KEY;
869 path = btrfs_alloc_path();
870 mutex_lock(&root->fs_info->alloc_mutex);
871 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
876 leaf = path->nodes[0];
877 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
879 if (found_key.objectid != bytenr ||
880 found_key.type != BTRFS_EXTENT_ITEM_KEY) {
886 *min_generation = (u64)-1;
889 leaf = path->nodes[0];
890 nritems = btrfs_header_nritems(leaf);
891 if (path->slots[0] >= nritems) {
892 ret = btrfs_next_leaf(extent_root, path);
899 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
900 if (found_key.objectid != bytenr)
903 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
908 ref_item = btrfs_item_ptr(leaf, path->slots[0],
909 struct btrfs_extent_ref);
910 ref_generation = btrfs_ref_generation(leaf, ref_item);
912 * For (parent_gen > 0 && parent_gen > ref_gen):
914 * we reach here through the oldest root, therefore
915 * all other reference from same snapshot should have
916 * a larger generation.
918 if ((root_objectid != btrfs_ref_root(leaf, ref_item)) ||
919 (parent_gen > 0 && parent_gen > ref_generation) ||
920 (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
921 ref_objectid != btrfs_ref_objectid(leaf, ref_item))) {
928 if (*min_generation > ref_generation)
929 *min_generation = ref_generation;
935 mutex_unlock(&root->fs_info->alloc_mutex);
936 btrfs_free_path(path);
940 int btrfs_cross_ref_exists(struct btrfs_trans_handle *trans,
941 struct btrfs_root *root,
942 struct btrfs_key *key, u64 bytenr)
944 struct btrfs_root *old_root;
945 struct btrfs_path *path = NULL;
946 struct extent_buffer *eb;
947 struct btrfs_file_extent_item *item;
955 BUG_ON(trans == NULL);
956 BUG_ON(key->type != BTRFS_EXTENT_DATA_KEY);
957 ret = get_reference_status(root, bytenr, 0, key->objectid,
958 &min_generation, &ref_count);
965 old_root = root->dirty_root->root;
966 ref_generation = old_root->root_key.offset;
968 /* all references are created in running transaction */
969 if (min_generation > ref_generation) {
974 path = btrfs_alloc_path();
980 path->skip_locking = 1;
981 /* if no item found, the extent is referenced by other snapshot */
982 ret = btrfs_search_slot(NULL, old_root, key, path, 0, 0);
987 item = btrfs_item_ptr(eb, path->slots[0],
988 struct btrfs_file_extent_item);
989 if (btrfs_file_extent_type(eb, item) != BTRFS_FILE_EXTENT_REG ||
990 btrfs_file_extent_disk_bytenr(eb, item) != bytenr) {
995 for (level = BTRFS_MAX_LEVEL - 1; level >= -1; level--) {
997 eb = path->nodes[level];
1000 extent_start = eb->start;
1002 extent_start = bytenr;
1004 ret = get_reference_status(root, extent_start, ref_generation,
1005 0, &min_generation, &ref_count);
1009 if (ref_count != 1) {
1014 ref_generation = btrfs_header_generation(eb);
1019 btrfs_free_path(path);
1023 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1024 struct extent_buffer *buf, int cache_ref)
1028 struct btrfs_key key;
1029 struct btrfs_file_extent_item *fi;
1034 int nr_file_extents = 0;
1036 if (!root->ref_cows)
1039 level = btrfs_header_level(buf);
1040 nritems = btrfs_header_nritems(buf);
1041 for (i = 0; i < nritems; i++) {
1045 btrfs_item_key_to_cpu(buf, &key, i);
1046 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1048 fi = btrfs_item_ptr(buf, i,
1049 struct btrfs_file_extent_item);
1050 if (btrfs_file_extent_type(buf, fi) ==
1051 BTRFS_FILE_EXTENT_INLINE)
1053 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1054 if (disk_bytenr == 0)
1057 if (buf != root->commit_root)
1060 mutex_lock(&root->fs_info->alloc_mutex);
1061 ret = __btrfs_inc_extent_ref(trans, root, disk_bytenr,
1062 btrfs_file_extent_disk_num_bytes(buf, fi),
1063 root->root_key.objectid, trans->transid,
1064 key.objectid, key.offset);
1065 mutex_unlock(&root->fs_info->alloc_mutex);
1072 bytenr = btrfs_node_blockptr(buf, i);
1073 btrfs_node_key_to_cpu(buf, &key, i);
1075 mutex_lock(&root->fs_info->alloc_mutex);
1076 ret = __btrfs_inc_extent_ref(trans, root, bytenr,
1077 btrfs_level_size(root, level - 1),
1078 root->root_key.objectid,
1080 level - 1, key.objectid);
1081 mutex_unlock(&root->fs_info->alloc_mutex);
1089 /* cache orignal leaf block's references */
1090 if (level == 0 && cache_ref && buf != root->commit_root) {
1091 struct btrfs_leaf_ref *ref;
1092 struct btrfs_extent_info *info;
1094 ref = btrfs_alloc_leaf_ref(root, nr_file_extents);
1100 ref->root_gen = root->root_key.offset;
1101 ref->bytenr = buf->start;
1102 ref->owner = btrfs_header_owner(buf);
1103 ref->generation = btrfs_header_generation(buf);
1104 ref->nritems = nr_file_extents;
1105 info = ref->extents;
1107 for (i = 0; nr_file_extents > 0 && i < nritems; i++) {
1109 btrfs_item_key_to_cpu(buf, &key, i);
1110 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1112 fi = btrfs_item_ptr(buf, i,
1113 struct btrfs_file_extent_item);
1114 if (btrfs_file_extent_type(buf, fi) ==
1115 BTRFS_FILE_EXTENT_INLINE)
1117 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1118 if (disk_bytenr == 0)
1121 info->bytenr = disk_bytenr;
1123 btrfs_file_extent_disk_num_bytes(buf, fi);
1124 info->objectid = key.objectid;
1125 info->offset = key.offset;
1129 BUG_ON(!root->ref_tree);
1130 ret = btrfs_add_leaf_ref(root, ref);
1132 btrfs_free_leaf_ref(root, ref);
1139 for (i =0; i < faili; i++) {
1142 btrfs_item_key_to_cpu(buf, &key, i);
1143 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
1145 fi = btrfs_item_ptr(buf, i,
1146 struct btrfs_file_extent_item);
1147 if (btrfs_file_extent_type(buf, fi) ==
1148 BTRFS_FILE_EXTENT_INLINE)
1150 disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
1151 if (disk_bytenr == 0)
1153 err = btrfs_free_extent(trans, root, disk_bytenr,
1154 btrfs_file_extent_disk_num_bytes(buf,
1158 bytenr = btrfs_node_blockptr(buf, i);
1159 err = btrfs_free_extent(trans, root, bytenr,
1160 btrfs_level_size(root, level - 1), 0);
1168 static int write_one_cache_group(struct btrfs_trans_handle *trans,
1169 struct btrfs_root *root,
1170 struct btrfs_path *path,
1171 struct btrfs_block_group_cache *cache)
1175 struct btrfs_root *extent_root = root->fs_info->extent_root;
1177 struct extent_buffer *leaf;
1179 ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
1184 leaf = path->nodes[0];
1185 bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
1186 write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
1187 btrfs_mark_buffer_dirty(leaf);
1188 btrfs_release_path(extent_root, path);
1190 finish_current_insert(trans, extent_root);
1191 pending_ret = del_pending_extents(trans, extent_root);
1200 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
1201 struct btrfs_root *root)
1203 struct btrfs_block_group_cache *cache, *entry;
1207 struct btrfs_path *path;
1210 path = btrfs_alloc_path();
1214 mutex_lock(&root->fs_info->alloc_mutex);
1217 spin_lock(&root->fs_info->block_group_cache_lock);
1218 for (n = rb_first(&root->fs_info->block_group_cache_tree);
1219 n; n = rb_next(n)) {
1220 entry = rb_entry(n, struct btrfs_block_group_cache,
1227 spin_unlock(&root->fs_info->block_group_cache_lock);
1232 last += cache->key.offset;
1234 err = write_one_cache_group(trans, root,
1237 * if we fail to write the cache group, we want
1238 * to keep it marked dirty in hopes that a later
1248 btrfs_free_path(path);
1249 mutex_unlock(&root->fs_info->alloc_mutex);
1253 static int update_space_info(struct btrfs_fs_info *info, u64 flags,
1254 u64 total_bytes, u64 bytes_used,
1255 struct btrfs_space_info **space_info)
1257 struct btrfs_space_info *found;
1259 found = __find_space_info(info, flags);
1261 found->total_bytes += total_bytes;
1262 found->bytes_used += bytes_used;
1264 *space_info = found;
1267 found = kmalloc(sizeof(*found), GFP_NOFS);
1271 list_add(&found->list, &info->space_info);
1272 INIT_LIST_HEAD(&found->block_groups);
1273 spin_lock_init(&found->lock);
1274 found->flags = flags;
1275 found->total_bytes = total_bytes;
1276 found->bytes_used = bytes_used;
1277 found->bytes_pinned = 0;
1279 found->force_alloc = 0;
1280 *space_info = found;
1284 static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
1286 u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 |
1287 BTRFS_BLOCK_GROUP_RAID1 |
1288 BTRFS_BLOCK_GROUP_RAID10 |
1289 BTRFS_BLOCK_GROUP_DUP);
1291 if (flags & BTRFS_BLOCK_GROUP_DATA)
1292 fs_info->avail_data_alloc_bits |= extra_flags;
1293 if (flags & BTRFS_BLOCK_GROUP_METADATA)
1294 fs_info->avail_metadata_alloc_bits |= extra_flags;
1295 if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
1296 fs_info->avail_system_alloc_bits |= extra_flags;
1300 static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags)
1302 u64 num_devices = root->fs_info->fs_devices->num_devices;
1304 if (num_devices == 1)
1305 flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
1306 if (num_devices < 4)
1307 flags &= ~BTRFS_BLOCK_GROUP_RAID10;
1309 if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
1310 (flags & (BTRFS_BLOCK_GROUP_RAID1 |
1311 BTRFS_BLOCK_GROUP_RAID10))) {
1312 flags &= ~BTRFS_BLOCK_GROUP_DUP;
1315 if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
1316 (flags & BTRFS_BLOCK_GROUP_RAID10)) {
1317 flags &= ~BTRFS_BLOCK_GROUP_RAID1;
1320 if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
1321 ((flags & BTRFS_BLOCK_GROUP_RAID1) |
1322 (flags & BTRFS_BLOCK_GROUP_RAID10) |
1323 (flags & BTRFS_BLOCK_GROUP_DUP)))
1324 flags &= ~BTRFS_BLOCK_GROUP_RAID0;
1328 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
1329 struct btrfs_root *extent_root, u64 alloc_bytes,
1330 u64 flags, int force)
1332 struct btrfs_space_info *space_info;
1338 flags = reduce_alloc_profile(extent_root, flags);
1340 space_info = __find_space_info(extent_root->fs_info, flags);
1342 ret = update_space_info(extent_root->fs_info, flags,
1346 BUG_ON(!space_info);
1348 if (space_info->force_alloc) {
1350 space_info->force_alloc = 0;
1352 if (space_info->full)
1355 thresh = div_factor(space_info->total_bytes, 6);
1357 (space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) <
1361 mutex_lock(&extent_root->fs_info->chunk_mutex);
1362 ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags);
1363 if (ret == -ENOSPC) {
1364 printk("space info full %Lu\n", flags);
1365 space_info->full = 1;
1370 ret = btrfs_make_block_group(trans, extent_root, 0, flags,
1371 BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes);
1375 mutex_unlock(&extent_root->fs_info->chunk_mutex);
1380 static int update_block_group(struct btrfs_trans_handle *trans,
1381 struct btrfs_root *root,
1382 u64 bytenr, u64 num_bytes, int alloc,
1385 struct btrfs_block_group_cache *cache;
1386 struct btrfs_fs_info *info = root->fs_info;
1387 u64 total = num_bytes;
1391 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1393 cache = btrfs_lookup_block_group(info, bytenr);
1397 byte_in_group = bytenr - cache->key.objectid;
1398 WARN_ON(byte_in_group > cache->key.offset);
1400 spin_lock(&cache->lock);
1402 old_val = btrfs_block_group_used(&cache->item);
1403 num_bytes = min(total, cache->key.offset - byte_in_group);
1405 old_val += num_bytes;
1406 cache->space_info->bytes_used += num_bytes;
1407 btrfs_set_block_group_used(&cache->item, old_val);
1408 spin_unlock(&cache->lock);
1410 old_val -= num_bytes;
1411 cache->space_info->bytes_used -= num_bytes;
1412 btrfs_set_block_group_used(&cache->item, old_val);
1413 spin_unlock(&cache->lock);
1416 ret = btrfs_add_free_space(cache, bytenr,
1423 bytenr += num_bytes;
1428 static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
1430 struct btrfs_block_group_cache *cache;
1432 cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
1436 return cache->key.objectid;
1440 int btrfs_update_pinned_extents(struct btrfs_root *root,
1441 u64 bytenr, u64 num, int pin)
1444 struct btrfs_block_group_cache *cache;
1445 struct btrfs_fs_info *fs_info = root->fs_info;
1447 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1449 set_extent_dirty(&fs_info->pinned_extents,
1450 bytenr, bytenr + num - 1, GFP_NOFS);
1452 clear_extent_dirty(&fs_info->pinned_extents,
1453 bytenr, bytenr + num - 1, GFP_NOFS);
1456 cache = btrfs_lookup_block_group(fs_info, bytenr);
1458 u64 first = first_logical_byte(root, bytenr);
1459 WARN_ON(first < bytenr);
1460 len = min(first - bytenr, num);
1462 len = min(num, cache->key.offset -
1463 (bytenr - cache->key.objectid));
1467 spin_lock(&cache->lock);
1468 cache->pinned += len;
1469 cache->space_info->bytes_pinned += len;
1470 spin_unlock(&cache->lock);
1472 fs_info->total_pinned += len;
1475 spin_lock(&cache->lock);
1476 cache->pinned -= len;
1477 cache->space_info->bytes_pinned -= len;
1478 spin_unlock(&cache->lock);
1480 fs_info->total_pinned -= len;
1488 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy)
1493 struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents;
1497 ret = find_first_extent_bit(pinned_extents, last,
1498 &start, &end, EXTENT_DIRTY);
1501 set_extent_dirty(copy, start, end, GFP_NOFS);
1507 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
1508 struct btrfs_root *root,
1509 struct extent_io_tree *unpin)
1514 struct btrfs_block_group_cache *cache;
1516 mutex_lock(&root->fs_info->alloc_mutex);
1518 ret = find_first_extent_bit(unpin, 0, &start, &end,
1522 btrfs_update_pinned_extents(root, start, end + 1 - start, 0);
1523 clear_extent_dirty(unpin, start, end, GFP_NOFS);
1524 cache = btrfs_lookup_block_group(root->fs_info, start);
1526 btrfs_add_free_space(cache, start, end - start + 1);
1527 if (need_resched()) {
1528 mutex_unlock(&root->fs_info->alloc_mutex);
1530 mutex_lock(&root->fs_info->alloc_mutex);
1533 mutex_unlock(&root->fs_info->alloc_mutex);
1537 static int finish_current_insert(struct btrfs_trans_handle *trans,
1538 struct btrfs_root *extent_root)
1542 struct btrfs_fs_info *info = extent_root->fs_info;
1543 struct extent_buffer *eb;
1544 struct btrfs_path *path;
1545 struct btrfs_key ins;
1546 struct btrfs_disk_key first;
1547 struct btrfs_extent_item extent_item;
1552 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1553 btrfs_set_stack_extent_refs(&extent_item, 1);
1554 btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY);
1555 path = btrfs_alloc_path();
1558 ret = find_first_extent_bit(&info->extent_ins, 0, &start,
1559 &end, EXTENT_LOCKED);
1563 ins.objectid = start;
1564 ins.offset = end + 1 - start;
1565 err = btrfs_insert_item(trans, extent_root, &ins,
1566 &extent_item, sizeof(extent_item));
1567 clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1570 eb = btrfs_find_create_tree_block(extent_root, ins.objectid,
1573 if (!btrfs_buffer_uptodate(eb, trans->transid))
1574 btrfs_read_buffer(eb, trans->transid);
1576 btrfs_tree_lock(eb);
1577 level = btrfs_header_level(eb);
1579 btrfs_item_key(eb, &first, 0);
1581 btrfs_node_key(eb, &first, 0);
1583 btrfs_tree_unlock(eb);
1584 free_extent_buffer(eb);
1586 * the first key is just a hint, so the race we've created
1587 * against reading it is fine
1589 err = btrfs_insert_extent_backref(trans, extent_root, path,
1590 start, extent_root->root_key.objectid,
1592 btrfs_disk_key_objectid(&first));
1594 if (need_resched()) {
1595 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1597 mutex_lock(&extent_root->fs_info->alloc_mutex);
1600 btrfs_free_path(path);
1604 static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes,
1605 int is_data, int pending)
1609 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1611 struct extent_buffer *buf;
1616 buf = btrfs_find_tree_block(root, bytenr, num_bytes);
1618 /* we can reuse a block if it hasn't been written
1619 * and it is from this transaction. We can't
1620 * reuse anything from the tree log root because
1621 * it has tiny sub-transactions.
1623 if (btrfs_buffer_uptodate(buf, 0) &&
1624 btrfs_try_tree_lock(buf)) {
1626 root->fs_info->running_transaction->transid;
1627 u64 header_transid =
1628 btrfs_header_generation(buf);
1629 if (btrfs_header_owner(buf) !=
1630 BTRFS_TREE_LOG_OBJECTID &&
1631 header_transid == transid &&
1632 !btrfs_header_flag(buf,
1633 BTRFS_HEADER_FLAG_WRITTEN)) {
1634 clean_tree_block(NULL, root, buf);
1635 btrfs_tree_unlock(buf);
1636 free_extent_buffer(buf);
1639 btrfs_tree_unlock(buf);
1641 free_extent_buffer(buf);
1644 btrfs_update_pinned_extents(root, bytenr, num_bytes, 1);
1646 set_extent_bits(&root->fs_info->pending_del,
1647 bytenr, bytenr + num_bytes - 1,
1648 EXTENT_LOCKED, GFP_NOFS);
1655 * remove an extent from the root, returns 0 on success
1657 static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
1658 *root, u64 bytenr, u64 num_bytes,
1659 u64 root_objectid, u64 ref_generation,
1660 u64 owner_objectid, u64 owner_offset, int pin,
1663 struct btrfs_path *path;
1664 struct btrfs_key key;
1665 struct btrfs_fs_info *info = root->fs_info;
1666 struct btrfs_root *extent_root = info->extent_root;
1667 struct extent_buffer *leaf;
1669 int extent_slot = 0;
1670 int found_extent = 0;
1672 struct btrfs_extent_item *ei;
1675 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
1676 key.objectid = bytenr;
1677 btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
1678 key.offset = num_bytes;
1679 path = btrfs_alloc_path();
1684 ret = lookup_extent_backref(trans, extent_root, path,
1685 bytenr, root_objectid,
1687 owner_objectid, owner_offset, 1);
1689 struct btrfs_key found_key;
1690 extent_slot = path->slots[0];
1691 while(extent_slot > 0) {
1693 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1695 if (found_key.objectid != bytenr)
1697 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
1698 found_key.offset == num_bytes) {
1702 if (path->slots[0] - extent_slot > 5)
1706 ret = btrfs_del_item(trans, extent_root, path);
1708 btrfs_print_leaf(extent_root, path->nodes[0]);
1710 printk("Unable to find ref byte nr %Lu root %Lu "
1711 " gen %Lu owner %Lu offset %Lu\n", bytenr,
1712 root_objectid, ref_generation, owner_objectid,
1715 if (!found_extent) {
1716 btrfs_release_path(extent_root, path);
1717 ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1);
1721 extent_slot = path->slots[0];
1724 leaf = path->nodes[0];
1725 ei = btrfs_item_ptr(leaf, extent_slot,
1726 struct btrfs_extent_item);
1727 refs = btrfs_extent_refs(leaf, ei);
1730 btrfs_set_extent_refs(leaf, ei, refs);
1732 btrfs_mark_buffer_dirty(leaf);
1734 if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) {
1735 /* if the back ref and the extent are next to each other
1736 * they get deleted below in one shot
1738 path->slots[0] = extent_slot;
1740 } else if (found_extent) {
1741 /* otherwise delete the extent back ref */
1742 ret = btrfs_del_item(trans, extent_root, path);
1744 /* if refs are 0, we need to setup the path for deletion */
1746 btrfs_release_path(extent_root, path);
1747 ret = btrfs_search_slot(trans, extent_root, &key, path,
1758 #ifdef BIO_RW_DISCARD
1759 u64 map_length = num_bytes;
1760 struct btrfs_multi_bio *multi = NULL;
1764 ret = pin_down_bytes(root, bytenr, num_bytes,
1765 owner_objectid >= BTRFS_FIRST_FREE_OBJECTID, 0);
1771 /* block accounting for super block */
1772 spin_lock_irq(&info->delalloc_lock);
1773 super_used = btrfs_super_bytes_used(&info->super_copy);
1774 btrfs_set_super_bytes_used(&info->super_copy,
1775 super_used - num_bytes);
1776 spin_unlock_irq(&info->delalloc_lock);
1778 /* block accounting for root item */
1779 root_used = btrfs_root_used(&root->root_item);
1780 btrfs_set_root_used(&root->root_item,
1781 root_used - num_bytes);
1782 ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
1787 ret = update_block_group(trans, root, bytenr, num_bytes, 0,
1791 #ifdef BIO_RW_DISCARD
1792 /* Tell the block device(s) that the sectors can be discarded */
1793 ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
1794 bytenr, &map_length, &multi, 0);
1796 struct btrfs_bio_stripe *stripe = multi->stripes;
1799 if (map_length > num_bytes)
1800 map_length = num_bytes;
1802 for (i = 0; i < multi->num_stripes; i++, stripe++) {
1803 blkdev_issue_discard(stripe->dev->bdev,
1804 stripe->physical >> 9,
1811 btrfs_free_path(path);
1812 finish_current_insert(trans, extent_root);
1817 * find all the blocks marked as pending in the radix tree and remove
1818 * them from the extent map
1820 static int del_pending_extents(struct btrfs_trans_handle *trans, struct
1821 btrfs_root *extent_root)
1827 struct extent_io_tree *pending_del;
1828 struct extent_io_tree *pinned_extents;
1830 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
1831 pending_del = &extent_root->fs_info->pending_del;
1832 pinned_extents = &extent_root->fs_info->pinned_extents;
1835 ret = find_first_extent_bit(pending_del, 0, &start, &end,
1839 clear_extent_bits(pending_del, start, end, EXTENT_LOCKED,
1841 if (!test_range_bit(&extent_root->fs_info->extent_ins,
1842 start, end, EXTENT_LOCKED, 0)) {
1843 btrfs_update_pinned_extents(extent_root, start,
1844 end + 1 - start, 1);
1845 ret = __free_extent(trans, extent_root,
1846 start, end + 1 - start,
1847 extent_root->root_key.objectid,
1850 clear_extent_bits(&extent_root->fs_info->extent_ins,
1851 start, end, EXTENT_LOCKED, GFP_NOFS);
1856 if (need_resched()) {
1857 mutex_unlock(&extent_root->fs_info->alloc_mutex);
1859 mutex_lock(&extent_root->fs_info->alloc_mutex);
1866 * remove an extent from the root, returns 0 on success
1868 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
1869 struct btrfs_root *root, u64 bytenr,
1870 u64 num_bytes, u64 root_objectid,
1871 u64 ref_generation, u64 owner_objectid,
1872 u64 owner_offset, int pin)
1874 struct btrfs_root *extent_root = root->fs_info->extent_root;
1878 WARN_ON(num_bytes < root->sectorsize);
1879 if (!root->ref_cows)
1882 if (root == extent_root) {
1883 pin_down_bytes(root, bytenr, num_bytes, 0, 1);
1886 /* if metadata always pin */
1887 if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
1888 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
1889 struct btrfs_block_group_cache *cache;
1891 /* btrfs_free_reserved_extent */
1892 cache = btrfs_lookup_block_group(root->fs_info, bytenr);
1894 btrfs_add_free_space(cache, bytenr, num_bytes);
1900 /* if data pin when any transaction has committed this */
1901 if (ref_generation != trans->transid)
1904 ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid,
1905 ref_generation, owner_objectid, owner_offset,
1908 finish_current_insert(trans, root->fs_info->extent_root);
1909 pending_ret = del_pending_extents(trans, root->fs_info->extent_root);
1910 return ret ? ret : pending_ret;
1913 int btrfs_free_extent(struct btrfs_trans_handle *trans,
1914 struct btrfs_root *root, u64 bytenr,
1915 u64 num_bytes, u64 root_objectid,
1916 u64 ref_generation, u64 owner_objectid,
1917 u64 owner_offset, int pin)
1921 maybe_lock_mutex(root);
1922 ret = __btrfs_free_extent(trans, root, bytenr, num_bytes,
1923 root_objectid, ref_generation,
1924 owner_objectid, owner_offset, pin);
1925 maybe_unlock_mutex(root);
1929 static u64 stripe_align(struct btrfs_root *root, u64 val)
1931 u64 mask = ((u64)root->stripesize - 1);
1932 u64 ret = (val + mask) & ~mask;
1937 * walks the btree of allocated extents and find a hole of a given size.
1938 * The key ins is changed to record the hole:
1939 * ins->objectid == block start
1940 * ins->flags = BTRFS_EXTENT_ITEM_KEY
1941 * ins->offset == number of blocks
1942 * Any available blocks before search_start are skipped.
1944 static int noinline find_free_extent(struct btrfs_trans_handle *trans,
1945 struct btrfs_root *orig_root,
1946 u64 num_bytes, u64 empty_size,
1947 u64 search_start, u64 search_end,
1948 u64 hint_byte, struct btrfs_key *ins,
1949 u64 exclude_start, u64 exclude_nr,
1953 u64 orig_search_start;
1954 struct btrfs_root * root = orig_root->fs_info->extent_root;
1955 struct btrfs_fs_info *info = root->fs_info;
1956 u64 total_needed = num_bytes;
1957 u64 *last_ptr = NULL;
1958 struct btrfs_block_group_cache *block_group;
1959 int chunk_alloc_done = 0;
1960 int empty_cluster = 2 * 1024 * 1024;
1961 int allowed_chunk_alloc = 0;
1963 WARN_ON(num_bytes < root->sectorsize);
1964 btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
1966 if (orig_root->ref_cows || empty_size)
1967 allowed_chunk_alloc = 1;
1969 if (data & BTRFS_BLOCK_GROUP_METADATA) {
1970 last_ptr = &root->fs_info->last_alloc;
1971 empty_cluster = 256 * 1024;
1974 if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD))
1975 last_ptr = &root->fs_info->last_data_alloc;
1977 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
1978 last_ptr = &root->fs_info->last_log_alloc;
1979 if (!last_ptr == 0 && root->fs_info->last_alloc) {
1980 *last_ptr = root->fs_info->last_alloc + empty_cluster;
1986 hint_byte = *last_ptr;
1988 empty_size += empty_cluster;
1991 search_start = max(search_start, first_logical_byte(root, 0));
1992 orig_search_start = search_start;
1994 if (search_end == (u64)-1)
1995 search_end = btrfs_super_total_bytes(&info->super_copy);
1997 search_start = max(search_start, hint_byte);
1998 total_needed += empty_size;
2001 block_group = btrfs_lookup_block_group(info, search_start);
2004 * Ok this looks a little tricky, buts its really simple. First if we
2005 * didn't find a block group obviously we want to start over.
2006 * Secondly, if the block group we found does not match the type we
2007 * need, and we have a last_ptr and its not 0, chances are the last
2008 * allocation we made was at the end of the block group, so lets go
2009 * ahead and skip the looking through the rest of the block groups and
2010 * start at the beginning. This helps with metadata allocations,
2011 * since you are likely to have a bunch of data block groups to search
2012 * through first before you realize that you need to start over, so go
2013 * ahead and start over and save the time.
2015 if (!block_group || (!block_group_bits(block_group, data) &&
2016 last_ptr && *last_ptr)) {
2017 if (search_start != orig_search_start) {
2018 if (last_ptr && *last_ptr)
2020 search_start = orig_search_start;
2022 } else if (!chunk_alloc_done && allowed_chunk_alloc) {
2023 ret = do_chunk_alloc(trans, root,
2024 num_bytes + 2 * 1024 * 1024,
2027 struct btrfs_space_info *info;
2029 info = __find_space_info(root->fs_info, data);
2033 chunk_alloc_done = 1;
2034 search_start = orig_search_start;
2043 * this is going to seach through all of the existing block groups it
2044 * can find, so if we don't find something we need to see if we can
2045 * allocate what we need.
2047 ret = find_free_space(root, &block_group, &search_start,
2048 total_needed, data);
2049 if (ret == -ENOSPC) {
2051 * instead of allocating, start at the original search start
2052 * and see if there is something to be found, if not then we
2055 if (search_start != orig_search_start) {
2056 if (last_ptr && *last_ptr) {
2058 total_needed += empty_cluster;
2060 search_start = orig_search_start;
2065 * we've already allocated, we're pretty screwed
2067 if (chunk_alloc_done) {
2069 } else if (!allowed_chunk_alloc && block_group &&
2070 block_group_bits(block_group, data)) {
2071 block_group->space_info->force_alloc = 1;
2073 } else if (!allowed_chunk_alloc) {
2077 ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024,
2083 chunk_alloc_done = 1;
2085 search_start = block_group->key.objectid +
2086 block_group->key.offset;
2088 search_start = orig_search_start;
2095 search_start = stripe_align(root, search_start);
2096 ins->objectid = search_start;
2097 ins->offset = num_bytes;
2099 if (ins->objectid + num_bytes >= search_end) {
2100 search_start = orig_search_start;
2101 if (chunk_alloc_done) {
2108 if (ins->objectid + num_bytes >
2109 block_group->key.objectid + block_group->key.offset) {
2110 if (search_start == orig_search_start && chunk_alloc_done) {
2114 search_start = block_group->key.objectid +
2115 block_group->key.offset;
2119 if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start &&
2120 ins->objectid < exclude_start + exclude_nr)) {
2121 search_start = exclude_start + exclude_nr;
2125 if (!(data & BTRFS_BLOCK_GROUP_DATA))
2126 trans->block_group = block_group;
2128 ins->offset = num_bytes;
2130 *last_ptr = ins->objectid + ins->offset;
2132 btrfs_super_total_bytes(&root->fs_info->super_copy))
2141 static void dump_space_info(struct btrfs_space_info *info, u64 bytes)
2143 struct btrfs_block_group_cache *cache;
2144 struct list_head *l;
2146 printk(KERN_INFO "space_info has %Lu free, is %sfull\n",
2147 info->total_bytes - info->bytes_used - info->bytes_pinned,
2148 (info->full) ? "" : "not ");
2150 spin_lock(&info->lock);
2151 list_for_each(l, &info->block_groups) {
2152 cache = list_entry(l, struct btrfs_block_group_cache, list);
2153 spin_lock(&cache->lock);
2154 printk(KERN_INFO "block group %Lu has %Lu bytes, %Lu used "
2156 cache->key.objectid, cache->key.offset,
2157 btrfs_block_group_used(&cache->item), cache->pinned);
2158 btrfs_dump_free_space(cache, bytes);
2159 spin_unlock(&cache->lock);
2161 spin_unlock(&info->lock);
2163 static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2164 struct btrfs_root *root,
2165 u64 num_bytes, u64 min_alloc_size,
2166 u64 empty_size, u64 hint_byte,
2167 u64 search_end, struct btrfs_key *ins,
2171 u64 search_start = 0;
2173 struct btrfs_fs_info *info = root->fs_info;
2174 struct btrfs_block_group_cache *cache;
2177 alloc_profile = info->avail_data_alloc_bits &
2178 info->data_alloc_profile;
2179 data = BTRFS_BLOCK_GROUP_DATA | alloc_profile;
2180 } else if (root == root->fs_info->chunk_root) {
2181 alloc_profile = info->avail_system_alloc_bits &
2182 info->system_alloc_profile;
2183 data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile;
2185 alloc_profile = info->avail_metadata_alloc_bits &
2186 info->metadata_alloc_profile;
2187 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
2190 data = reduce_alloc_profile(root, data);
2192 * the only place that sets empty_size is btrfs_realloc_node, which
2193 * is not called recursively on allocations
2195 if (empty_size || root->ref_cows) {
2196 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
2197 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2199 BTRFS_BLOCK_GROUP_METADATA |
2200 (info->metadata_alloc_profile &
2201 info->avail_metadata_alloc_bits), 0);
2203 ret = do_chunk_alloc(trans, root->fs_info->extent_root,
2204 num_bytes + 2 * 1024 * 1024, data, 0);
2207 WARN_ON(num_bytes < root->sectorsize);
2208 ret = find_free_extent(trans, root, num_bytes, empty_size,
2209 search_start, search_end, hint_byte, ins,
2210 trans->alloc_exclude_start,
2211 trans->alloc_exclude_nr, data);
2213 if (ret == -ENOSPC && num_bytes > min_alloc_size) {
2214 num_bytes = num_bytes >> 1;
2215 num_bytes = num_bytes & ~(root->sectorsize - 1);
2216 num_bytes = max(num_bytes, min_alloc_size);
2217 do_chunk_alloc(trans, root->fs_info->extent_root,
2218 num_bytes, data, 1);
2222 struct btrfs_space_info *sinfo;
2224 sinfo = __find_space_info(root->fs_info, data);
2225 printk("allocation failed flags %Lu, wanted %Lu\n",
2227 dump_space_info(sinfo, num_bytes);
2230 cache = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2232 printk(KERN_ERR "Unable to find block group for %Lu\n", ins->objectid);
2236 ret = btrfs_remove_free_space(cache, ins->objectid, ins->offset);
2241 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
2243 struct btrfs_block_group_cache *cache;
2245 maybe_lock_mutex(root);
2246 cache = btrfs_lookup_block_group(root->fs_info, start);
2248 printk(KERN_ERR "Unable to find block group for %Lu\n", start);
2249 maybe_unlock_mutex(root);
2252 btrfs_add_free_space(cache, start, len);
2253 maybe_unlock_mutex(root);
2257 int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
2258 struct btrfs_root *root,
2259 u64 num_bytes, u64 min_alloc_size,
2260 u64 empty_size, u64 hint_byte,
2261 u64 search_end, struct btrfs_key *ins,
2265 maybe_lock_mutex(root);
2266 ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size,
2267 empty_size, hint_byte, search_end, ins,
2269 maybe_unlock_mutex(root);
2273 static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2274 struct btrfs_root *root,
2275 u64 root_objectid, u64 ref_generation,
2276 u64 owner, u64 owner_offset,
2277 struct btrfs_key *ins)
2283 u64 num_bytes = ins->offset;
2285 struct btrfs_fs_info *info = root->fs_info;
2286 struct btrfs_root *extent_root = info->extent_root;
2287 struct btrfs_extent_item *extent_item;
2288 struct btrfs_extent_ref *ref;
2289 struct btrfs_path *path;
2290 struct btrfs_key keys[2];
2292 /* block accounting for super block */
2293 spin_lock_irq(&info->delalloc_lock);
2294 super_used = btrfs_super_bytes_used(&info->super_copy);
2295 btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes);
2296 spin_unlock_irq(&info->delalloc_lock);
2298 /* block accounting for root item */
2299 root_used = btrfs_root_used(&root->root_item);
2300 btrfs_set_root_used(&root->root_item, root_used + num_bytes);
2302 if (root == extent_root) {
2303 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
2304 ins->objectid + ins->offset - 1,
2305 EXTENT_LOCKED, GFP_NOFS);
2309 memcpy(&keys[0], ins, sizeof(*ins));
2310 keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
2311 owner, owner_offset);
2312 keys[1].objectid = ins->objectid;
2313 keys[1].type = BTRFS_EXTENT_REF_KEY;
2314 sizes[0] = sizeof(*extent_item);
2315 sizes[1] = sizeof(*ref);
2317 path = btrfs_alloc_path();
2320 ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
2324 extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2325 struct btrfs_extent_item);
2326 btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
2327 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
2328 struct btrfs_extent_ref);
2330 btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
2331 btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
2332 btrfs_set_ref_objectid(path->nodes[0], ref, owner);
2333 btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
2335 btrfs_mark_buffer_dirty(path->nodes[0]);
2337 trans->alloc_exclude_start = 0;
2338 trans->alloc_exclude_nr = 0;
2339 btrfs_free_path(path);
2340 finish_current_insert(trans, extent_root);
2341 pending_ret = del_pending_extents(trans, extent_root);
2351 ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0);
2353 printk("update block group failed for %Lu %Lu\n",
2354 ins->objectid, ins->offset);
2361 int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans,
2362 struct btrfs_root *root,
2363 u64 root_objectid, u64 ref_generation,
2364 u64 owner, u64 owner_offset,
2365 struct btrfs_key *ins)
2369 if (root_objectid == BTRFS_TREE_LOG_OBJECTID)
2371 maybe_lock_mutex(root);
2372 ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid,
2373 ref_generation, owner,
2375 maybe_unlock_mutex(root);
2380 * this is used by the tree logging recovery code. It records that
2381 * an extent has been allocated and makes sure to clear the free
2382 * space cache bits as well
2384 int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
2385 struct btrfs_root *root,
2386 u64 root_objectid, u64 ref_generation,
2387 u64 owner, u64 owner_offset,
2388 struct btrfs_key *ins)
2391 struct btrfs_block_group_cache *block_group;
2393 maybe_lock_mutex(root);
2394 block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
2395 cache_block_group(root, block_group);
2397 ret = btrfs_remove_free_space(block_group, ins->objectid, ins->offset);
2400 ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid,
2401 ref_generation, owner,
2403 maybe_unlock_mutex(root);
2408 * finds a free extent and does all the dirty work required for allocation
2409 * returns the key for the extent through ins, and a tree buffer for
2410 * the first block of the extent through buf.
2412 * returns 0 if everything worked, non-zero otherwise.
2414 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
2415 struct btrfs_root *root,
2416 u64 num_bytes, u64 min_alloc_size,
2417 u64 root_objectid, u64 ref_generation,
2418 u64 owner, u64 owner_offset,
2419 u64 empty_size, u64 hint_byte,
2420 u64 search_end, struct btrfs_key *ins, u64 data)
2424 maybe_lock_mutex(root);
2426 ret = __btrfs_reserve_extent(trans, root, num_bytes,
2427 min_alloc_size, empty_size, hint_byte,
2428 search_end, ins, data);
2430 if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
2431 ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid,
2432 ref_generation, owner,
2437 maybe_unlock_mutex(root);
2441 struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
2442 struct btrfs_root *root,
2443 u64 bytenr, u32 blocksize)
2445 struct extent_buffer *buf;
2447 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
2449 return ERR_PTR(-ENOMEM);
2450 btrfs_set_header_generation(buf, trans->transid);
2451 btrfs_tree_lock(buf);
2452 clean_tree_block(trans, root, buf);
2453 btrfs_set_buffer_uptodate(buf);
2454 if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
2455 set_extent_dirty(&root->dirty_log_pages, buf->start,
2456 buf->start + buf->len - 1, GFP_NOFS);
2458 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
2459 buf->start + buf->len - 1, GFP_NOFS);
2461 trans->blocks_used++;
2466 * helper function to allocate a block for a given tree
2467 * returns the tree buffer or NULL.
2469 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
2470 struct btrfs_root *root,
2479 struct btrfs_key ins;
2481 struct extent_buffer *buf;
2483 ret = btrfs_alloc_extent(trans, root, blocksize, blocksize,
2484 root_objectid, ref_generation,
2485 level, first_objectid, empty_size, hint,
2489 return ERR_PTR(ret);
2492 buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize);
2496 int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
2497 struct btrfs_root *root, struct extent_buffer *leaf)
2500 u64 leaf_generation;
2501 struct btrfs_key key;
2502 struct btrfs_file_extent_item *fi;
2507 BUG_ON(!btrfs_is_leaf(leaf));
2508 nritems = btrfs_header_nritems(leaf);
2509 leaf_owner = btrfs_header_owner(leaf);
2510 leaf_generation = btrfs_header_generation(leaf);
2512 for (i = 0; i < nritems; i++) {
2516 btrfs_item_key_to_cpu(leaf, &key, i);
2517 if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
2519 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
2520 if (btrfs_file_extent_type(leaf, fi) ==
2521 BTRFS_FILE_EXTENT_INLINE)
2524 * FIXME make sure to insert a trans record that
2525 * repeats the snapshot del on crash
2527 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
2528 if (disk_bytenr == 0)
2531 mutex_lock(&root->fs_info->alloc_mutex);
2532 ret = __btrfs_free_extent(trans, root, disk_bytenr,
2533 btrfs_file_extent_disk_num_bytes(leaf, fi),
2534 leaf_owner, leaf_generation,
2535 key.objectid, key.offset, 0);
2536 mutex_unlock(&root->fs_info->alloc_mutex);
2538 atomic_inc(&root->fs_info->throttle_gen);
2539 wake_up(&root->fs_info->transaction_throttle);
2547 static int noinline cache_drop_leaf_ref(struct btrfs_trans_handle *trans,
2548 struct btrfs_root *root,
2549 struct btrfs_leaf_ref *ref)
2553 struct btrfs_extent_info *info = ref->extents;
2555 for (i = 0; i < ref->nritems; i++) {
2556 mutex_lock(&root->fs_info->alloc_mutex);
2557 ret = __btrfs_free_extent(trans, root,
2558 info->bytenr, info->num_bytes,
2559 ref->owner, ref->generation,
2560 info->objectid, info->offset, 0);
2561 mutex_unlock(&root->fs_info->alloc_mutex);
2563 atomic_inc(&root->fs_info->throttle_gen);
2564 wake_up(&root->fs_info->transaction_throttle);
2574 int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len,
2579 ret = lookup_extent_ref(NULL, root, start, len, refs);
2582 #if 0 // some debugging code in case we see problems here
2583 /* if the refs count is one, it won't get increased again. But
2584 * if the ref count is > 1, someone may be decreasing it at
2585 * the same time we are.
2588 struct extent_buffer *eb = NULL;
2589 eb = btrfs_find_create_tree_block(root, start, len);
2591 btrfs_tree_lock(eb);
2593 mutex_lock(&root->fs_info->alloc_mutex);
2594 ret = lookup_extent_ref(NULL, root, start, len, refs);
2596 mutex_unlock(&root->fs_info->alloc_mutex);
2599 btrfs_tree_unlock(eb);
2600 free_extent_buffer(eb);
2603 printk("block %llu went down to one during drop_snap\n",
2604 (unsigned long long)start);
2615 * helper function for drop_snapshot, this walks down the tree dropping ref
2616 * counts as it goes.
2618 static int noinline walk_down_tree(struct btrfs_trans_handle *trans,
2619 struct btrfs_root *root,
2620 struct btrfs_path *path, int *level)
2626 struct extent_buffer *next;
2627 struct extent_buffer *cur;
2628 struct extent_buffer *parent;
2629 struct btrfs_leaf_ref *ref;
2634 WARN_ON(*level < 0);
2635 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2636 ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start,
2637 path->nodes[*level]->len, &refs);
2643 * walk down to the last node level and free all the leaves
2645 while(*level >= 0) {
2646 WARN_ON(*level < 0);
2647 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2648 cur = path->nodes[*level];
2650 if (btrfs_header_level(cur) != *level)
2653 if (path->slots[*level] >=
2654 btrfs_header_nritems(cur))
2657 ret = btrfs_drop_leaf_ref(trans, root, cur);
2661 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2662 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2663 blocksize = btrfs_level_size(root, *level - 1);
2665 ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs);
2668 parent = path->nodes[*level];
2669 root_owner = btrfs_header_owner(parent);
2670 root_gen = btrfs_header_generation(parent);
2671 path->slots[*level]++;
2673 mutex_lock(&root->fs_info->alloc_mutex);
2674 ret = __btrfs_free_extent(trans, root, bytenr,
2675 blocksize, root_owner,
2678 mutex_unlock(&root->fs_info->alloc_mutex);
2680 atomic_inc(&root->fs_info->throttle_gen);
2681 wake_up(&root->fs_info->transaction_throttle);
2687 * at this point, we have a single ref, and since the
2688 * only place referencing this extent is a dead root
2689 * the reference count should never go higher.
2690 * So, we don't need to check it again
2693 struct btrfs_key key;
2694 btrfs_node_key_to_cpu(cur, &key, path->slots[*level]);
2695 ref = btrfs_lookup_leaf_ref(root, bytenr);
2697 ret = cache_drop_leaf_ref(trans, root, ref);
2699 btrfs_remove_leaf_ref(root, ref);
2700 btrfs_free_leaf_ref(root, ref);
2704 if (printk_ratelimit())
2705 printk("leaf ref miss for bytenr %llu\n",
2706 (unsigned long long)bytenr);
2708 next = btrfs_find_tree_block(root, bytenr, blocksize);
2709 if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) {
2710 free_extent_buffer(next);
2712 next = read_tree_block(root, bytenr, blocksize,
2717 * this is a debugging check and can go away
2718 * the ref should never go all the way down to 1
2721 ret = lookup_extent_ref(NULL, root, bytenr, blocksize,
2727 WARN_ON(*level <= 0);
2728 if (path->nodes[*level-1])
2729 free_extent_buffer(path->nodes[*level-1]);
2730 path->nodes[*level-1] = next;
2731 *level = btrfs_header_level(next);
2732 path->slots[*level] = 0;
2736 WARN_ON(*level < 0);
2737 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2739 if (path->nodes[*level] == root->node) {
2740 parent = path->nodes[*level];
2741 bytenr = path->nodes[*level]->start;
2743 parent = path->nodes[*level + 1];
2744 bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]);
2747 blocksize = btrfs_level_size(root, *level);
2748 root_owner = btrfs_header_owner(parent);
2749 root_gen = btrfs_header_generation(parent);
2751 mutex_lock(&root->fs_info->alloc_mutex);
2752 ret = __btrfs_free_extent(trans, root, bytenr, blocksize,
2753 root_owner, root_gen, 0, 0, 1);
2754 free_extent_buffer(path->nodes[*level]);
2755 path->nodes[*level] = NULL;
2758 mutex_unlock(&root->fs_info->alloc_mutex);
2765 * helper for dropping snapshots. This walks back up the tree in the path
2766 * to find the first node higher up where we haven't yet gone through
2769 static int noinline walk_up_tree(struct btrfs_trans_handle *trans,
2770 struct btrfs_root *root,
2771 struct btrfs_path *path, int *level)
2775 struct btrfs_root_item *root_item = &root->root_item;
2780 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2781 slot = path->slots[i];
2782 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
2783 struct extent_buffer *node;
2784 struct btrfs_disk_key disk_key;
2785 node = path->nodes[i];
2788 WARN_ON(*level == 0);
2789 btrfs_node_key(node, &disk_key, path->slots[i]);
2790 memcpy(&root_item->drop_progress,
2791 &disk_key, sizeof(disk_key));
2792 root_item->drop_level = i;
2795 if (path->nodes[*level] == root->node) {
2796 root_owner = root->root_key.objectid;
2798 btrfs_header_generation(path->nodes[*level]);
2800 struct extent_buffer *node;
2801 node = path->nodes[*level + 1];
2802 root_owner = btrfs_header_owner(node);
2803 root_gen = btrfs_header_generation(node);
2805 ret = btrfs_free_extent(trans, root,
2806 path->nodes[*level]->start,
2807 path->nodes[*level]->len,
2808 root_owner, root_gen, 0, 0, 1);
2810 free_extent_buffer(path->nodes[*level]);
2811 path->nodes[*level] = NULL;
2819 * drop the reference count on the tree rooted at 'snap'. This traverses
2820 * the tree freeing any blocks that have a ref count of zero after being
2823 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
2829 struct btrfs_path *path;
2832 struct btrfs_root_item *root_item = &root->root_item;
2834 WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex));
2835 path = btrfs_alloc_path();
2838 level = btrfs_header_level(root->node);
2840 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2841 path->nodes[level] = root->node;
2842 extent_buffer_get(root->node);
2843 path->slots[level] = 0;
2845 struct btrfs_key key;
2846 struct btrfs_disk_key found_key;
2847 struct extent_buffer *node;
2849 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2850 level = root_item->drop_level;
2851 path->lowest_level = level;
2852 wret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2857 node = path->nodes[level];
2858 btrfs_node_key(node, &found_key, path->slots[level]);
2859 WARN_ON(memcmp(&found_key, &root_item->drop_progress,
2860 sizeof(found_key)));
2862 * unlock our path, this is safe because only this
2863 * function is allowed to delete this snapshot
2865 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
2866 if (path->nodes[i] && path->locks[i]) {
2868 btrfs_tree_unlock(path->nodes[i]);
2873 wret = walk_down_tree(trans, root, path, &level);
2879 wret = walk_up_tree(trans, root, path, &level);
2884 if (trans->transaction->in_commit) {
2888 atomic_inc(&root->fs_info->throttle_gen);
2889 wake_up(&root->fs_info->transaction_throttle);
2891 for (i = 0; i <= orig_level; i++) {
2892 if (path->nodes[i]) {
2893 free_extent_buffer(path->nodes[i]);
2894 path->nodes[i] = NULL;
2898 btrfs_free_path(path);
2902 int btrfs_free_block_groups(struct btrfs_fs_info *info)
2904 struct btrfs_block_group_cache *block_group;
2907 mutex_lock(&info->alloc_mutex);
2908 spin_lock(&info->block_group_cache_lock);
2909 while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
2910 block_group = rb_entry(n, struct btrfs_block_group_cache,
2913 btrfs_remove_free_space_cache(block_group);
2914 rb_erase(&block_group->cache_node,
2915 &info->block_group_cache_tree);
2916 spin_lock(&block_group->space_info->lock);
2917 list_del(&block_group->list);
2918 spin_unlock(&block_group->space_info->lock);
2921 spin_unlock(&info->block_group_cache_lock);
2922 mutex_unlock(&info->alloc_mutex);
2926 static unsigned long calc_ra(unsigned long start, unsigned long last,
2929 return min(last, start + nr - 1);
2932 static int noinline relocate_inode_pages(struct inode *inode, u64 start,
2937 unsigned long last_index;
2940 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2941 struct file_ra_state *ra;
2942 unsigned long total_read = 0;
2943 unsigned long ra_pages;
2944 struct btrfs_ordered_extent *ordered;
2945 struct btrfs_trans_handle *trans;
2947 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2949 mutex_lock(&inode->i_mutex);
2950 i = start >> PAGE_CACHE_SHIFT;
2951 last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
2953 ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages;
2955 file_ra_state_init(ra, inode->i_mapping);
2957 for (; i <= last_index; i++) {
2958 if (total_read % ra_pages == 0) {
2959 btrfs_force_ra(inode->i_mapping, ra, NULL, i,
2960 calc_ra(i, last_index, ra_pages));
2964 if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode))
2965 goto truncate_racing;
2966 page = grab_cache_page(inode->i_mapping, i);
2970 if (!PageUptodate(page)) {
2971 btrfs_readpage(NULL, page);
2973 if (!PageUptodate(page)) {
2975 page_cache_release(page);
2979 wait_on_page_writeback(page);
2981 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2982 page_end = page_start + PAGE_CACHE_SIZE - 1;
2983 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
2985 ordered = btrfs_lookup_ordered_extent(inode, page_start);
2987 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
2989 page_cache_release(page);
2990 btrfs_start_ordered_extent(inode, ordered, 1);
2991 btrfs_put_ordered_extent(ordered);
2994 set_page_extent_mapped(page);
2997 * make sure page_mkwrite is called for this page if userland
2998 * wants to change it from mmap
3000 clear_page_dirty_for_io(page);
3002 btrfs_set_extent_delalloc(inode, page_start, page_end);
3003 set_page_dirty(page);
3005 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
3007 page_cache_release(page);
3011 /* we have to start the IO in order to get the ordered extents
3012 * instantiated. This allows the relocation to code to wait
3013 * for all the ordered extents to hit the disk.
3015 * Otherwise, it would constantly loop over the same extents
3016 * because the old ones don't get deleted until the IO is
3019 btrfs_fdatawrite_range(inode->i_mapping, start, start + len - 1,
3022 trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1);
3024 btrfs_end_transaction(trans, BTRFS_I(inode)->root);
3025 mark_inode_dirty(inode);
3027 mutex_unlock(&inode->i_mutex);
3031 vmtruncate(inode, inode->i_size);
3032 balance_dirty_pages_ratelimited_nr(inode->i_mapping,
3038 * The back references tell us which tree holds a ref on a block,
3039 * but it is possible for the tree root field in the reference to
3040 * reflect the original root before a snapshot was made. In this
3041 * case we should search through all the children of a given root
3042 * to find potential holders of references on a block.
3044 * Instead, we do something a little less fancy and just search
3045 * all the roots for a given key/block combination.
3047 static int find_root_for_ref(struct btrfs_root *root,
3048 struct btrfs_path *path,
3049 struct btrfs_key *key0,
3052 struct btrfs_root **found_root,
3055 struct btrfs_key root_location;
3056 struct btrfs_root *cur_root = *found_root;
3057 struct btrfs_file_extent_item *file_extent;
3058 u64 root_search_start = BTRFS_FS_TREE_OBJECTID;
3062 root_location.offset = (u64)-1;
3063 root_location.type = BTRFS_ROOT_ITEM_KEY;
3064 path->lowest_level = level;
3067 ret = btrfs_search_slot(NULL, cur_root, key0, path, 0, 0);
3069 if (ret == 0 && file_key) {
3070 struct extent_buffer *leaf = path->nodes[0];
3071 file_extent = btrfs_item_ptr(leaf, path->slots[0],
3072 struct btrfs_file_extent_item);
3073 if (btrfs_file_extent_type(leaf, file_extent) ==
3074 BTRFS_FILE_EXTENT_REG) {
3076 btrfs_file_extent_disk_bytenr(leaf,
3079 } else if (!file_key) {
3080 if (path->nodes[level])
3081 found_bytenr = path->nodes[level]->start;
3084 btrfs_release_path(cur_root, path);
3086 if (found_bytenr == bytenr) {
3087 *found_root = cur_root;
3091 ret = btrfs_search_root(root->fs_info->tree_root,
3092 root_search_start, &root_search_start);
3096 root_location.objectid = root_search_start;
3097 cur_root = btrfs_read_fs_root_no_name(root->fs_info,
3105 path->lowest_level = 0;
3110 * note, this releases the path
3112 static int noinline relocate_one_reference(struct btrfs_root *extent_root,
3113 struct btrfs_path *path,
3114 struct btrfs_key *extent_key,
3115 u64 *last_file_objectid,
3116 u64 *last_file_offset,
3117 u64 *last_file_root,
3120 struct inode *inode;
3121 struct btrfs_root *found_root;
3122 struct btrfs_key root_location;
3123 struct btrfs_key found_key;
3124 struct btrfs_extent_ref *ref;
3132 WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex));
3134 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
3135 struct btrfs_extent_ref);
3136 ref_root = btrfs_ref_root(path->nodes[0], ref);
3137 ref_gen = btrfs_ref_generation(path->nodes[0], ref);
3138 ref_objectid = btrfs_ref_objectid(path->nodes[0], ref);
3139 ref_offset = btrfs_ref_offset(path->nodes[0], ref);
3140 btrfs_release_path(extent_root, path);
3142 root_location.objectid = ref_root;
3144 root_location.offset = 0;
3146 root_location.offset = (u64)-1;
3147 root_location.type = BTRFS_ROOT_ITEM_KEY;
3149 found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
3151 BUG_ON(!found_root);
3152 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3154 if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
3155 found_key.objectid = ref_objectid;
3156 found_key.type = BTRFS_EXTENT_DATA_KEY;
3157 found_key.offset = ref_offset;
3160 if (last_extent == extent_key->objectid &&
3161 *last_file_objectid == ref_objectid &&
3162 *last_file_offset == ref_offset &&
3163 *last_file_root == ref_root)
3166 ret = find_root_for_ref(extent_root, path, &found_key,
3167 level, 1, &found_root,
3168 extent_key->objectid);
3173 if (last_extent == extent_key->objectid &&
3174 *last_file_objectid == ref_objectid &&
3175 *last_file_offset == ref_offset &&
3176 *last_file_root == ref_root)
3179 inode = btrfs_iget_locked(extent_root->fs_info->sb,
3180 ref_objectid, found_root);
3181 if (inode->i_state & I_NEW) {
3182 /* the inode and parent dir are two different roots */
3183 BTRFS_I(inode)->root = found_root;
3184 BTRFS_I(inode)->location.objectid = ref_objectid;
3185 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
3186 BTRFS_I(inode)->location.offset = 0;
3187 btrfs_read_locked_inode(inode);
3188 unlock_new_inode(inode);
3191 /* this can happen if the reference is not against
3192 * the latest version of the tree root
3194 if (is_bad_inode(inode))
3197 *last_file_objectid = inode->i_ino;
3198 *last_file_root = found_root->root_key.objectid;
3199 *last_file_offset = ref_offset;
3201 relocate_inode_pages(inode, ref_offset, extent_key->offset);
3204 struct btrfs_trans_handle *trans;
3205 struct extent_buffer *eb;
3208 eb = read_tree_block(found_root, extent_key->objectid,
3209 extent_key->offset, 0);
3210 btrfs_tree_lock(eb);
3211 level = btrfs_header_level(eb);
3214 btrfs_item_key_to_cpu(eb, &found_key, 0);
3216 btrfs_node_key_to_cpu(eb, &found_key, 0);
3218 btrfs_tree_unlock(eb);
3219 free_extent_buffer(eb);
3221 ret = find_root_for_ref(extent_root, path, &found_key,
3222 level, 0, &found_root,
3223 extent_key->objectid);
3229 * right here almost anything could happen to our key,
3230 * but that's ok. The cow below will either relocate it
3231 * or someone else will have relocated it. Either way,
3232 * it is in a different spot than it was before and
3236 trans = btrfs_start_transaction(found_root, 1);
3238 if (found_root == extent_root->fs_info->extent_root ||
3239 found_root == extent_root->fs_info->chunk_root ||
3240 found_root == extent_root->fs_info->dev_root) {
3242 mutex_lock(&extent_root->fs_info->alloc_mutex);
3245 path->lowest_level = level;
3247 ret = btrfs_search_slot(trans, found_root, &found_key, path,
3249 path->lowest_level = 0;
3250 btrfs_release_path(found_root, path);
3252 if (found_root == found_root->fs_info->extent_root)
3253 btrfs_extent_post_op(trans, found_root);
3255 mutex_unlock(&extent_root->fs_info->alloc_mutex);
3257 btrfs_end_transaction(trans, found_root);
3261 mutex_lock(&extent_root->fs_info->alloc_mutex);
3265 static int noinline del_extent_zero(struct btrfs_root *extent_root,
3266 struct btrfs_path *path,
3267 struct btrfs_key *extent_key)
3270 struct btrfs_trans_handle *trans;
3272 trans = btrfs_start_transaction(extent_root, 1);
3273 ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1);
3280 ret = btrfs_del_item(trans, extent_root, path);
3282 btrfs_end_transaction(trans, extent_root);
3286 static int noinline relocate_one_extent(struct btrfs_root *extent_root,
3287 struct btrfs_path *path,
3288 struct btrfs_key *extent_key)
3290 struct btrfs_key key;
3291 struct btrfs_key found_key;
3292 struct extent_buffer *leaf;
3293 u64 last_file_objectid = 0;
3294 u64 last_file_root = 0;
3295 u64 last_file_offset = (u64)-1;
3296 u64 last_extent = 0;
3301 if (extent_key->objectid == 0) {
3302 ret = del_extent_zero(extent_root, path, extent_key);
3305 key.objectid = extent_key->objectid;
3306 key.type = BTRFS_EXTENT_REF_KEY;
3310 ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
3316 leaf = path->nodes[0];
3317 nritems = btrfs_header_nritems(leaf);
3318 if (path->slots[0] == nritems) {
3319 ret = btrfs_next_leaf(extent_root, path);
3326 leaf = path->nodes[0];
3329 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3330 if (found_key.objectid != extent_key->objectid) {
3334 if (found_key.type != BTRFS_EXTENT_REF_KEY) {
3338 key.offset = found_key.offset + 1;
3339 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3341 ret = relocate_one_reference(extent_root, path, extent_key,
3342 &last_file_objectid,
3344 &last_file_root, last_extent);
3347 last_extent = extent_key->objectid;
3351 btrfs_release_path(extent_root, path);
3355 static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
3358 u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
3359 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
3361 num_devices = root->fs_info->fs_devices->num_devices;
3362 if (num_devices == 1) {
3363 stripped |= BTRFS_BLOCK_GROUP_DUP;
3364 stripped = flags & ~stripped;
3366 /* turn raid0 into single device chunks */
3367 if (flags & BTRFS_BLOCK_GROUP_RAID0)
3370 /* turn mirroring into duplication */
3371 if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
3372 BTRFS_BLOCK_GROUP_RAID10))
3373 return stripped | BTRFS_BLOCK_GROUP_DUP;
3376 /* they already had raid on here, just return */
3377 if (flags & stripped)
3380 stripped |= BTRFS_BLOCK_GROUP_DUP;
3381 stripped = flags & ~stripped;
3383 /* switch duplicated blocks with raid1 */
3384 if (flags & BTRFS_BLOCK_GROUP_DUP)
3385 return stripped | BTRFS_BLOCK_GROUP_RAID1;
3387 /* turn single device chunks into raid0 */
3388 return stripped | BTRFS_BLOCK_GROUP_RAID0;
3393 int __alloc_chunk_for_shrink(struct btrfs_root *root,
3394 struct btrfs_block_group_cache *shrink_block_group,
3397 struct btrfs_trans_handle *trans;
3398 u64 new_alloc_flags;
3401 spin_lock(&shrink_block_group->lock);
3402 if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
3403 spin_unlock(&shrink_block_group->lock);
3404 mutex_unlock(&root->fs_info->alloc_mutex);
3406 trans = btrfs_start_transaction(root, 1);
3407 mutex_lock(&root->fs_info->alloc_mutex);
3408 spin_lock(&shrink_block_group->lock);
3410 new_alloc_flags = update_block_group_flags(root,
3411 shrink_block_group->flags);
3412 if (new_alloc_flags != shrink_block_group->flags) {
3414 btrfs_block_group_used(&shrink_block_group->item);
3416 calc = shrink_block_group->key.offset;
3418 spin_unlock(&shrink_block_group->lock);
3420 do_chunk_alloc(trans, root->fs_info->extent_root,
3421 calc + 2 * 1024 * 1024, new_alloc_flags, force);
3423 mutex_unlock(&root->fs_info->alloc_mutex);
3424 btrfs_end_transaction(trans, root);
3425 mutex_lock(&root->fs_info->alloc_mutex);
3427 spin_unlock(&shrink_block_group->lock);
3431 int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
3433 struct btrfs_trans_handle *trans;
3434 struct btrfs_root *tree_root = root->fs_info->tree_root;
3435 struct btrfs_path *path;
3438 u64 shrink_last_byte;
3439 struct btrfs_block_group_cache *shrink_block_group;
3440 struct btrfs_key key;
3441 struct btrfs_key found_key;
3442 struct extent_buffer *leaf;
3447 mutex_lock(&root->fs_info->alloc_mutex);
3448 shrink_block_group = btrfs_lookup_block_group(root->fs_info,
3450 BUG_ON(!shrink_block_group);
3452 shrink_last_byte = shrink_block_group->key.objectid +
3453 shrink_block_group->key.offset;
3455 shrink_block_group->space_info->total_bytes -=
3456 shrink_block_group->key.offset;
3457 path = btrfs_alloc_path();
3458 root = root->fs_info->extent_root;
3461 printk("btrfs relocating block group %llu flags %llu\n",
3462 (unsigned long long)shrink_start,
3463 (unsigned long long)shrink_block_group->flags);
3465 __alloc_chunk_for_shrink(root, shrink_block_group, 1);
3469 shrink_block_group->ro = 1;
3473 key.objectid = shrink_start;
3476 cur_byte = key.objectid;
3478 mutex_unlock(&root->fs_info->alloc_mutex);
3480 btrfs_start_delalloc_inodes(root);
3481 btrfs_wait_ordered_extents(tree_root, 0);
3483 mutex_lock(&root->fs_info->alloc_mutex);
3485 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3489 ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY);
3494 leaf = path->nodes[0];
3495 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3496 if (found_key.objectid + found_key.offset > shrink_start &&
3497 found_key.objectid < shrink_last_byte) {
3498 cur_byte = found_key.objectid;
3499 key.objectid = cur_byte;
3502 btrfs_release_path(root, path);
3505 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3510 leaf = path->nodes[0];
3511 nritems = btrfs_header_nritems(leaf);
3512 if (path->slots[0] >= nritems) {
3513 ret = btrfs_next_leaf(root, path);
3520 leaf = path->nodes[0];
3521 nritems = btrfs_header_nritems(leaf);
3524 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3526 if (found_key.objectid >= shrink_last_byte)
3529 if (progress && need_resched()) {
3530 memcpy(&key, &found_key, sizeof(key));
3532 btrfs_release_path(root, path);
3533 btrfs_search_slot(NULL, root, &key, path, 0, 0);
3539 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY ||
3540 found_key.objectid + found_key.offset <= cur_byte) {
3541 memcpy(&key, &found_key, sizeof(key));
3548 cur_byte = found_key.objectid + found_key.offset;
3549 key.objectid = cur_byte;
3550 btrfs_release_path(root, path);
3551 ret = relocate_one_extent(root, path, &found_key);
3552 __alloc_chunk_for_shrink(root, shrink_block_group, 0);
3555 btrfs_release_path(root, path);
3557 if (total_found > 0) {
3558 printk("btrfs relocate found %llu last extent was %llu\n",
3559 (unsigned long long)total_found,
3560 (unsigned long long)found_key.objectid);
3561 mutex_unlock(&root->fs_info->alloc_mutex);
3562 trans = btrfs_start_transaction(tree_root, 1);
3563 btrfs_commit_transaction(trans, tree_root);
3565 btrfs_clean_old_snapshots(tree_root);
3567 btrfs_start_delalloc_inodes(root);
3568 btrfs_wait_ordered_extents(tree_root, 0);
3570 trans = btrfs_start_transaction(tree_root, 1);
3571 btrfs_commit_transaction(trans, tree_root);
3572 mutex_lock(&root->fs_info->alloc_mutex);
3577 * we've freed all the extents, now remove the block
3578 * group item from the tree
3580 mutex_unlock(&root->fs_info->alloc_mutex);
3582 trans = btrfs_start_transaction(root, 1);
3584 mutex_lock(&root->fs_info->alloc_mutex);
3585 memcpy(&key, &shrink_block_group->key, sizeof(key));
3587 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3591 btrfs_end_transaction(trans, root);
3595 spin_lock(&root->fs_info->block_group_cache_lock);
3596 rb_erase(&shrink_block_group->cache_node,
3597 &root->fs_info->block_group_cache_tree);
3598 spin_unlock(&root->fs_info->block_group_cache_lock);
3600 ret = btrfs_remove_free_space(shrink_block_group, key.objectid,
3603 btrfs_end_transaction(trans, root);
3607 memset(shrink_block_group, 0, sizeof(*shrink_block_group));
3608 kfree(shrink_block_group);
3611 btrfs_del_item(trans, root, path);
3612 btrfs_release_path(root, path);
3613 mutex_unlock(&root->fs_info->alloc_mutex);
3614 btrfs_commit_transaction(trans, root);
3616 mutex_lock(&root->fs_info->alloc_mutex);
3618 /* the code to unpin extents might set a few bits in the free
3619 * space cache for this range again
3622 ret = btrfs_remove_free_space(shrink_block_group, key.objectid,
3625 btrfs_free_path(path);
3626 mutex_unlock(&root->fs_info->alloc_mutex);
3630 int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path,
3631 struct btrfs_key *key)
3634 struct btrfs_key found_key;
3635 struct extent_buffer *leaf;
3638 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
3643 slot = path->slots[0];
3644 leaf = path->nodes[0];
3645 if (slot >= btrfs_header_nritems(leaf)) {
3646 ret = btrfs_next_leaf(root, path);
3653 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3655 if (found_key.objectid >= key->objectid &&
3656 found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
3667 int btrfs_read_block_groups(struct btrfs_root *root)
3669 struct btrfs_path *path;
3671 struct btrfs_block_group_cache *cache;
3672 struct btrfs_fs_info *info = root->fs_info;
3673 struct btrfs_space_info *space_info;
3674 struct btrfs_key key;
3675 struct btrfs_key found_key;
3676 struct extent_buffer *leaf;
3678 root = info->extent_root;
3681 btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3682 path = btrfs_alloc_path();
3686 mutex_lock(&root->fs_info->alloc_mutex);
3688 ret = find_first_block_group(root, path, &key);
3696 leaf = path->nodes[0];
3697 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3698 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3704 spin_lock_init(&cache->lock);
3705 INIT_LIST_HEAD(&cache->list);
3706 read_extent_buffer(leaf, &cache->item,
3707 btrfs_item_ptr_offset(leaf, path->slots[0]),
3708 sizeof(cache->item));
3709 memcpy(&cache->key, &found_key, sizeof(found_key));
3711 key.objectid = found_key.objectid + found_key.offset;
3712 btrfs_release_path(root, path);
3713 cache->flags = btrfs_block_group_flags(&cache->item);
3715 ret = update_space_info(info, cache->flags, found_key.offset,
3716 btrfs_block_group_used(&cache->item),
3719 cache->space_info = space_info;
3720 spin_lock(&space_info->lock);
3721 list_add(&cache->list, &space_info->block_groups);
3722 spin_unlock(&space_info->lock);
3724 ret = btrfs_add_block_group_cache(root->fs_info, cache);
3728 btrfs_super_total_bytes(&info->super_copy))
3733 btrfs_free_path(path);
3734 mutex_unlock(&root->fs_info->alloc_mutex);
3738 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
3739 struct btrfs_root *root, u64 bytes_used,
3740 u64 type, u64 chunk_objectid, u64 chunk_offset,
3744 struct btrfs_root *extent_root;
3745 struct btrfs_block_group_cache *cache;
3747 WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex));
3748 extent_root = root->fs_info->extent_root;
3750 root->fs_info->last_trans_new_blockgroup = trans->transid;
3752 cache = kzalloc(sizeof(*cache), GFP_NOFS);
3756 cache->key.objectid = chunk_offset;
3757 cache->key.offset = size;
3758 spin_lock_init(&cache->lock);
3759 INIT_LIST_HEAD(&cache->list);
3760 btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
3762 btrfs_set_block_group_used(&cache->item, bytes_used);
3763 btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
3764 cache->flags = type;
3765 btrfs_set_block_group_flags(&cache->item, type);
3767 ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
3768 &cache->space_info);
3770 spin_lock(&cache->space_info->lock);
3771 list_add(&cache->list, &cache->space_info->block_groups);
3772 spin_unlock(&cache->space_info->lock);
3774 ret = btrfs_add_block_group_cache(root->fs_info, cache);
3777 ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
3778 sizeof(cache->item));
3781 finish_current_insert(trans, extent_root);
3782 ret = del_pending_extents(trans, extent_root);
3784 set_avail_alloc_bits(extent_root->fs_info, type);